Re: [Patch v3 6/6] dt-bindings: thermal: Add dt binding for QCOM LMh

Bjorn Andersson
2021-07-10T04:21:34Z

On Thu 08 Jul 07:06 CDT 2021, Thara Gopinath wrote:

> Add dt binding documentation to describe Qualcomm
> Limits Management Hardware node.
>
> Signed-off-by: Thara Gopinath <thara.gopinath@linaro.org>
> ---
> .../devicetree/bindings/thermal/qcom-lmh.yaml | 100 ++++++++++++++++++
> 1 file changed, 100 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/thermal/qcom-lmh.yaml
>
> diff --git a/Documentation/devicetree/bindings/thermal/qcom-lmh.yaml b/Documentation/devicetree/bindings/thermal/qcom-lmh.yaml
> new file mode 100644
> index 000000000000..7f62bd3d543d
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/thermal/qcom-lmh.yaml
> @@ -0,0 +1,100 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +# Copyright 2021 Linaro Ltd.
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/thermal/qcom-lmh.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Qualcomm Limits Management Hardware(LMh)
> +
> +maintainers:
> + - Thara Gopinath <thara.gopinath@linaro.org>
> +
> +description:
> + Limits Management Hardware(LMh) is a hardware infrastructure on some
> + Qualcomm SoCs that can enforce temperature and current limits as
> + programmed by software for certain IPs like CPU.
> +
> +properties:
> + compatible:
> + enum:
> + - qcom,sdm845-lmh
> +
> + reg:
> + items:
> + - description: core registers
> +
> + interrupts:
> + maxItems: 1
> +
> + '#interrupt-cells':
> + const: 1
> +
> + interrupt-controller: true
> +
> + qcom,lmh-cpu-id:
> + description:
> + CPU id of the first cpu in the LMh cluster
> + $ref: /schemas/types.yaml#/definitions/uint32
> +
> + qcom,lmh-temperature-arm:
> + description:
> + An integer expressing temperature threshold in millicelsius at which
> + the LMh thermal FSM is engaged.

Do we know (by any public source) what "arm", "low" and "high" means
beyond that they somehow pokes the state machine?

> + $ref: /schemas/types.yaml#/definitions/int32
> +
> + qcom,lmh-temperature-low:
> + description:
> + An integer expressing temperature threshold in millicelsius at which
> + the LMh thermal FSM is engaged.
> + $ref: /schemas/types.yaml#/definitions/int32
> +
> + qcom,lmh-temperature-high:
> + description:
> + An integer expressing temperature threshold in millicelsius at which
> + the LMh thermal FSM is engaged.
> + $ref: /schemas/types.yaml#/definitions/int32
> +
> +required:
> + - compatible
> + - reg
> + - interrupts
> + - #interrupt-cells
> + - interrupt-controller
> + - qcom,lmh-cpu-id
> + - qcom,lmh-temperature-arm
> + - qcom,lmh-temperature-low
> + - qcom,lmh-temperature-high
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + #include <dt-bindings/interrupt-controller/arm-gic.h>
> + #include <dt-bindings/clock/qcom,rpmh.h>
> + #include <dt-bindings/interconnect/qcom,sdm845.h>

I don't see why you need qcom,rpmh.h or the interconnect include in this
example.

> +
> + lmh_cluster1: lmh@17d70800 {
> + compatible = "qcom,sdm845-lmh";
> + reg = <0 0x17d70800 0 0x401>;

#address- and #size-cells are 1 in the wrapper that validates the
examples, so drop the two zeros.

> + interrupts = <GIC_SPI 33 IRQ_TYPE_LEVEL_HIGH>;
> + qcom,lmh-cpu-id = <0x4>;
> + qcom,lmh-temperature-arm = <65000>;
> + qcom,lmh-temperature-low = <94500>;
> + qcom,lmh-temperature-high = <95000>;
> + interrupt-controller;
> + #interrupt-cells = <1>;
> + };
> + - |

This is a different example from the one above, if you intended that,
don't you need the #include of arm-gic.h here as well?

Regards,
Bjorn

> + lmh_cluster0: lmh@17d78800 {
> + compatible = "qcom,sdm845-lmh";
> + reg = <0 0x17d78800 0 0x401>;
> + interrupts = <GIC_SPI 32 IRQ_TYPE_LEVEL_HIGH>;
> + qcom,lmh-cpu-id = <0x0>;
> + qcom,lmh-temperature-arm = <65000>;
> + qcom,lmh-temperature-low = <94500>;
> + qcom,lmh-temperature-high = <95000>;
> + interrupt-controller;
> + #interrupt-cells = <1>;
> + };
> + - |
> --
> 2.25.1
>